1. Field of the Invention
The present invention relates to a waste-treating material, and more particularly to a material used for safely disposing of industrial wastes containing hazardous heavy metals and cyanides.
2. Description of the Prior Art
The common way to dispose of industrial wastes containing hazardous heavy metals and cyanides is by mixing them with cement and water and curing the mixture into a solid matrix which protects heavy metals and cyanides from leaching. The waste disposal which was prepared by using cement alone poses the secondary pollution of the environment if it is used indiscriminately. It has turned out that the solid of waste-cement mixture does not meet the requirement for leaching when tested according to California Wet Extraction Test Method. This is true in the case where wastes are lead- and cadmium-containing fly ash collected by an electrostatic precipitator or bag filter of an incinerator and copper- and nickel-containing sludge discharged from a water-treatment unit of a semiconductor factory. The fact that it is difficult to completely seal hazardous industrial wastes in a solid by means of cement alone has aroused a demand for a new material used for disposing of wastes safely without the fear of leaching which causes secondary pollution after land reclamation or ocean dumping.